DIPlus

Modified on 2008/04/24 11:55 by Administrator — Categorized as: Standard Indicators

Syntax

public static DIPlus Series(Bars bars, int period)

Parameter Description

bars	The Bars object
period	Indicator calculation period

Description

DIPlus is a component of the Directional Movement System developed by Welles Wilder. This system attempts to measure the strength of price movement in positive and negative directions, as well as the overall strength of the trend. DIPlus is normally used with the DIMinus, DX and ADX indicators and typically uses 14 periods.

The DIPlus value represents upward price movement as a percentage of true range. The more each up bar's price is equal to the true range, the larger the value of the DIPlus. The DIPlus and the DIMinus are not mirror images.

Interpretation

DIPlus measures a market's positive directional movement. If DIPlus is greater then DIMinus, prices have a stronger positive directional movement.
If prices rise for the number of periods specified then the DIPlus would be a high value and the DIMinus value would be near zero.
If prices fall for the number of periods specified then the DIPlus value would be near zero and DIMinus would have a high value.
If prices fluctuate for the number of periods specified, like in a trading range, then DIPlus and DIMinus will have similar values.
The greater the difference between the DIPlus and DIMinus the stronger the trend. The DX indicator takes advantage of this.

Calculation

+DI = Round( ( +DM / TR ) * 100 )

where,
DI+ = DIPlus
TR = TrueRange of current bar

The +DI is then smoothed over the period specified, the same way as a simple moving average, and +DM is calculated as follows:

For up trending days, +DM = today's high - yesterday's high
For down trending days, +DM = zero
For inside days, +DM = zero
For outside days, if today's high - yesterday's high, is greater than yesterday's low- today's low, then +DM = today's high - yesterday's high, otherwise +DM = zero
For upwards gap days, +DM = today's high - yesterday's high
For downwards gap days, +DM = zero

Example

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using WealthLab;
using WealthLab.Indicators;

namespace WealthLab.Strategies
{
	public class MyStrategy : WealthScript
	{
		protected override void Execute()
		{
			// Flag bars with dotted lines when DI+ is above 40
			
			ChartPane ADXPane = CreatePane( 50, true, true );
			PlotSeries( ADXPane, DIPlus.Series( Bars, 14 ), Color.Green, LineStyle.Solid, 2 );
			
			// DIPlus and DIMinus require stabilizing so start the bar count 3 to 4 times their period
			for(int bar = 50; bar < Bars.Count; bar++)
			{
				if( DIPlus.Series( Bars, 14 )[bar] > 40 )
					DrawLine( PricePane, bar, Low[bar], bar, 0, Color.Green, LineStyle.Dotted, 2 );
			}
		}
	}
}